Transfer of irrigation scheduling technology in Mexico

Abstract

In Mexico most of the agricultural production originates from large irrigation districts in the northern part of the country. This region is characterized by its semiarid desert climate with a winter rainy season dominated by frontal storms, and a summer monsoon season dominated by highly localized convective storms, yielding most of the annual precipitation. Essentially all irrigation needs must be met by surface water stored in various reservoirs. Precipitation is, therefore, the most important limiting factor in Mexico's agricultural production. Traditionally, long-time averages of statistical climate data from few and widely-spaced weather stations were used to determine frequency and amount of water applied, and the algorithms employed usually did not consider the effects of great spatial climate variability and plant physiology. In the past five years, great parts of Mexico, especially in the North, have been affected by severe water shortages resulting from insufficient precipitation (perhaps related to the `El Niño' phenomenon), combined with inefficient water resources management. Irrigation districts increasingly have to deal with the considerable uncertainty in water resources availability as a limiting factor in the decision making process. In order to address these irrigation water shortages, the Mexican National Water Commission and the Mexican Water Resources Institute are introducing new technologies using agrometeorological networks for more efficient, real-time irrigation scheduling in the main irrigation districts of Mexico. Validation plots established in one particular irrigation district (Carrizo Valley, Sinaloa), demonstrate water savings in the order of at least 20% without any appreciable decrease in crop yields.